The past seven days has been VERY wet along the coast, with some locations along the slopes of the Olympics and coast coastal mountains getting 10-20 inches)---see left panel below. The right panel shows the difference from normal for the same period--unusually wet coast. Some of the coastal river have hit or approached flood stage.
On Thursday and Friday, it was cool enough (and certainly wet enough) that the higher Cascades (above roughly 4000-4500 ft) got hit with several feet of snow (like three feet at Mount Baker ski area). But it was too warm for the lower ski areas (and particularly Snoqualmie) to get anything on their lower slopes.
And it was made worse last night, when a warm front came through, pushing the snow level up to around 5000 ft. The time-height cross section above Seattle shows this clearly (red is temperature in C, blue wind barbs, ordinate is pressure (850 is about 5000 ft), and time increases to the left (in UTC)
A weak frontal zone is now draped over the Northwest coast with light to moderate precipitation (see radar below)
Sunday morning will be a good time for outdoor activities (or to take part in the Seattle marathon) or to get across the passes. Later Sunday, a strong (but cooler) frontal system will move in and will it should be raining over the lowland by dinner time.